Genetic and QTL analyses of seed dormancy and preharvest sprouting resistance in the wheat germplasm CN10955

Abstract

The inheritance and genetic linkage analysis for seed dormancy and preharvest sprouting (PHS) resistance were carried out in an F8 recombinant inbred lines (RILs) derived from the cross between "CN19055" (white-grained, PHS-resistant) with locally adapted Australian cultivar "Annuello" (white-grained, PHS-susceptible). Seed dormancy was assessed as germination index (GI7) while assessment for preharvest sprouting resistance was based on whole head assay (sprouting index, SI) and visibly sprouted seeds (VI). Segregation analysis of the F2, F3 data from the glasshouse and the RIL population in 2004 and 2005 field data sets indicated that seed dormancy and PHS resistance in CN19055 is controlled by at least two genes. Heritabilities for GI7 and VI were high and moderate for SI. The most accurate method for assessing PHS resistance was achieved using VI and GI7 while SI exhibited large genotype by environment interaction. Two quantitative trait loci (QTLs) QPhs.dpivic.4A.1 and QPhs.dpivic.4A.2 were identified. On pooled data across four environments, the major QTL, QPhs.dpivic.4A.2, explained 45% of phenotypic variation for GI7, 43% for VI and 20% for SI, respectively. On the other hand, QPhs.dpivic.4A.1 which accounted for 31% of the phenotypic variation in GI7 in 2004 Horsham field trial, was not stable across environments. Physical mapping of two SSR markers, Xgwm937 and Xgwm894 linked to the major QTL for PHS resistance, using Chinese Spring deletions lines for chromosome 4AS and 4AL revealed that the markers were located in the deletion bins 4AL-12 and 4AL-13. The newly identified SSR markers (Xgwm937/Xgwm894) showed strong association with seed dormancy and PHS resistance in a range of wheat lines reputed to possess PHS resistance. The results suggest that Xgwm937/Xgwm894 could be used in marker-assisted selection (MAS) for incorporating preharvest sprouting resistance into elite wheat cultivars susceptible to PHS.

Maximizing the identification of QTL for pre-harvest sprouting resistance using seed dormancy measures in a white-grained hexaploid wheat population

“…Noda et al (2002) investigated another ABA responsive gene located on the long arm of chromosome 4A. QPhs.spa-4A, located in interval barc170-gwm397-wmc617a on 4A, is in a region associated with dormancy and preharvest sprouting resistance in numerous other QTL studies of hexaploid wheat (Flintham et al 2002;Torada et al 2005;Mares et al 2005;Tan et al 2006;Ogbonnaya et al 2008;Imtiaz et al 2008;Munkvold et al 2009;Rasul et al 2009;Kulwal et al 2010;Singh et al 2010Singh et al , 2012Lohwasser et al 2013). The locus was also identified in tetraploid ) and diploid (Nakamura et al 2007) wheat populations, and in an association mapping study (Kulwal et al 2012).…”

Meta-analysis of QTLs Involved in Pre-harvest Sprouting Tolerance and Dormancy in Bread Wheat

“…In several earlier studies, QTL for PHST/dormancy have also been detected on wheat chromosome 4AL Kato et al, 2001;Mares and Mrva, 2001;Mares et al, 2005;Chen et al, 2008;Ogbonnaya et al, 2008;Rasul et al, 2009;Nakamura et al, 2007;Singh et al, 2010;Lohwasser et al, 2005;Munkvold et al, 2009;Imtiaz et al, 2008). In wheat the three homoeologues of the GA20-oxidase gene TaGA20-ox1 (involved in gibberellin biosynthesis, controlling PHST/seed dormancy) have also been mapped to chromosomes 5BL, 5DL and 4AL (Appleford et al, 2006).…”

“…In earlier studies, grain dormancy has been shown to contribute to enhanced resistance to pre-harvest sprouting (Mares et al, 2009;Osa et al, 2003;Nakamura et al, 2007;Lohwasser et al, 2005;Torada et al, 2005;Ogbonnaya et al, 2008;Singh et al, 2010;Chen et al, 2008;Mares et al, 2005;Kottearachchi et al, 2008;Imtiaz et al, 2008;Munkvold et al, 2009;Fofana et al, 2009). This observation is confirmed by the results of the present study showing clustering of individual original QTLs for PHST and grain dormancy into a single cluster during meta-QTL analysis.…”

Analysis of Genetic Polymorphism of Korean Ginseng Cultivars and Foreign Accessions using SSR Markers

“…그러나, 인삼의 경우 외부 형태적 특성에 의한 유전자원의 평가는 유 전자형과 환경 간의 상호작용과 해가림 시설 등 재배방법에 따라서 표현형이 달라지기 때문에 적당하지 않다. 이러한 문 제점을 보완하기 위하여, 환경에 영향을 받지 않는 DNA 마 커를 이용한 유전적 다양성 분석과 품종 판별 에 관한 연구가 진행되어, 오이 (Bernet et al, 2003), 대청 , 유채 (Tommasini et al, 2003), 고추 (Kwon et al, 2005), 밀 (Noil et al, 2008), 사과 (Cho et al, 2010 (Wu and Tanksley, 1993;Saghai-Maroof et al, 1994;Morgante et al, 1995;Ogbonnaya et al, 2008).…”